The House is still plugging away on its budget proposal, but looming over lawmakers is a deep hole in the State Health Plan.

Over the 2012-2013 fiscal years, the state could be forced to add as much as $500 million to the plan to cover rising health care costs, House Majority Leader Hugh Holliman said Wednesday.

The plan, which provides health insurance to state employees, teachers and retirees, has serious problems with its structure. The plan has few of the younger, healthier people who help make a risk pool sustainable. Meanwhile, state employees do not pay premiums so the state has to pick up increased costs.

But this half a billion is merely the tip of the iceberg. Project out over the next four years, and the state is looking at having to find an additional $2 billionto keep the State Health Plan afloat. And that's not even counting the added financial burden soon to be imposed on the State Health Plan by Obamacare.